Clean rooms, safety workbenches, insulation chambers and fume hood compartments are used in many areas of industry and higher education, such as in research and development, in manufacturing and in quality control of products. All of these arrangements include a work cabinet with a work chamber. All have further in common that the person working with them is located outside the work chamber and thus in the vicinity of the work cabinet. The work chamber is further connected to a ventilation device and has transfer openings which connect the work chamber to the outside environment of the work cabinet. These transfer openings allow the materials being worked upon therein to be brought in and to be taken out. In addition, they also make it possible to reach into the work chamber. Transfer openings can be designed as freely accessible openings, as air locks, or as openings that are equipped with protective devices, for example, with rubber gloves.
Depending on the area of application for these devices, the ventilation device generates a below-ambient or above-ambient pressure level in the work chamber.
An above-ambient pressure is generated in the work chamber in all cases where the material being worked upon must not be contaminated under any circumstances. However, this requires that the material being worked upon creates no harmful effect in the surrounding area.
A below-ambient pressure is always generated in cases where the person outside the work cabinet needs to be protected from the substances inside the work chamber. As a result of the permanent under-pressure in the work chamber, air is continuously drawn from the ambient space into the work chamber through the transfer openings. In this way, one can prevent that toxic substances escape from the work chamber into the environment.
A setup of this kind is described for example in DE 3617965 A1. The device, which is referred to as a fume cupboard, includes a work table with a work cabinet. The work cabinet is formed by the work table surface, the right and left side walls, the rear wall, and the ceiling of the fume cupboard, as well as a transparent front wall. The work chamber, being thus completely enclosed, is accessible from the front side through a transfer opening.
In these work chambers, the material being worked upon is normally measured out in doses, transferred from one container to another, mixed, heated or cooled, and in some cases dissolved, for example adding substances in powder form to a solvent. In these processes, one needs to ensure when different substances are being treated that no mix-up or mislabeling can occur. Marking the individual containers correctly also includes that the exact fill quantity of the material being worked upon or substance is noted. The containers are normally marked by hand.
A variety of dosage-dispensing devices have been available for years, providing the capability to automatically dispense measured quantities of, e.g., a pulverous substance. The weight of the measured-out quantity is registered by means of a weighing cell. To mark the container, the weighing result can therefore be printed out on a printer together with an identifier means, for example a barcode or a matrix code. The carrier of the imprint is in most cases a self-adhesive label which can then be affixed to the container in addition to the hand-written information.
The foregoing procedure has the disadvantage that even when using all due diligence it is possible that a wrong label is affixed to one of the manually marked containers. Furthermore, the hand-marking takes a certain amount of time, which unnecessarily lengthens the entire dosage-dispensing process and therefore exposes the person involved in the activity, for example dealing with toxic or carcinogenic substances, to a high level of mental stress for an unnecessarily long time. In addition, the procedure which has just been described and which conforms to the safety regulations is sometimes disregarded by the operators in the sense that after each dispensing process, the workers will fetch the label from the printer outside of the cabinet into the work chamber without following the instructions for cleaning their hands.
It is therefore the object of the present invention to ensure that containers which have been filled with material being worked upon inside a work chamber are labeled quickly and safely with the output products of a printer. Furthermore, the laborious marking by hand is to be eliminated.